Corncob product and method of making the same



-"ras arena ear NORMAN E. DITMAN,

(JFNEW YORK, N.

GORNCOB PRODUCT AND METHOD OF MAKING THE SAME.

Ito Ibrawing. Application filed November To all whom it may concern: Be it known that I, NORMAN E. DrrMAN, citizen of the United States of America, r siding at New York, county and State of New York, have invented certain new and useful Improvements in Corncob Products and Methods of Making the Same, of which the following is a full, clear, and exact description.

The present invention relates to the use 1; of corncob cellulose, prepared from mature dried corn-cobs, as a starting material in the manufacture of threads, filaments, films, discs, lacquers, fillers, paints and coverings, imitation leather, bristles, preservative coverings and insulators, molded articles and plastic products of all forms, from cellulose esters,oel lulose acetates and cellulose formates in particular.

.The corn-cob cellulose employed may be unmodified, or in the form of hydrocellulose, ,oxycellulose, or corn-cob cellulose from v1s,- cose, mercerized corn-cob cellulose, anycupro-ammonium products of corn-cob cellulose or cormcob cellulose prepared as in my ,copending application No. 450,961.

The basic starting material in the present invention is dry mature corn cobs, that is 'corn has been shelled. -Oorn amount each year, to many to say, the cobs from which ripe dry mature cobs produced in United States, millions of tons, the greatbulk of which, are annually wasted, and hence they constitute an extremely cheap material.

The cobs can be used in their original state, or can be washed, crushedhto a coarse or fine meal. They can, if desired, be further purified by boiling in water, to which soda or other purifying agent may be added if desired, and they may be washed after this treatment if desired. They ma also be bleached by the use of sulfur dibxi sulfurous acid, chlorin, bleaching powder or other bleaching agents if desired. They may be converted into a purer form of cellulose by dissolving in caustic alkali and carbon vbisulfid, or cupro-ammonium hydroxid solution, and subsequently precipitated therefrom by acidsor acid salts if desired, .all as described in detail and as claimed 3 t w1ll be understood that after receivlng any of the-above reliminary treatments, the corn .cob material sho'uld.be dried,'before being converted into the esters.

in my copending lication No. 450,961, filed March 6, 1921.

18, 1922. Serial No. 601,912.

As pointed out in my copending application above identified, corn cobs contain certain' other components besides cellulose, some of which other components which are capable of undergoing reaction in a measure similar to cellulose. In the present invention, when corn cobs, in their mature state, whether raw or partially purified (as by comminuting, boiling in water, boiling in dilute alkalies, bleaching, etc.,) are sub: jected to processes for the esterification (acetylation, etc), of the cellulose, certain of these other substances appear to be modi-' fied to a considerable extent, so that these may be converted, (in part at least) into substances which become soluble in the solvents of the cellulose esters. These reaction products give desirable properties (for some purposes) to the cellulose acetate formed. The acetylatio'n can be accomplished by any one of the usual methods :-e. g., with glacial acetic acid, acetic anhydride and sulphuric acid, or by the use of any suitable lcatalyzeror condensing medium other than sulphuric acid-or by the substitution or addition of any other chemical or substances 1 which may be used in the process of acetylation.

Emample 1.-F0rmatz'o n of cellulose acetate.

Corn-cob cellulose, prepared as above described from mature dried (bleached if desired) is dried. One part of 7 this material is treated with four parts each of acetic acid and acetic anhydride and to 4 parts of sulphuric acid of 66 B. strength. The mixture, during the reaction, is kept below 50. The mass is allowed to remain at 40-45 for 12-24 hours, when the nearly colorless, thick liquid mass thus ob tained is poured into a large volume of water, and the precipitate is thoroughly washed and dried.

This product is then dissolved in any of the known celluloseacetate solvents such as acetone, glacial acetic acid, lactic acid. pyridine, nitrobenzene, epichlorhydrin, formic acid, acetylene tetrachloride, tetrachlorethane, ethyl acetate or chloroform and alcohol.

This solution may then be forced through spinarets, slits or into moulds. Solidification may be accomplished by evaporation or precipitation may be aided by the use of any of the known precipitants, such as water,

corn-cobs,

- benz'ol, alcohol, carbon tetrachloride or toluene.

Ewdmple 2..Formatln of cellulose acetate.

' T0100 kgs. of dry corn-cob cellulose, preferably. bleached, is added in one portion: a

- mixture of acetic anhydride equivalent to on the cellulose, the

' y it becomes plastic 270 130.310 kg's. of absolute acetic anhydride, .390 to 410 kgs'. glacial acetic acid and 3 to 5 litres commercial sulphuric acid of 66 B. strength. The acetylating mixture is poured temperature of the being preferably mainacetylating fluid C. The mixture is stirred tained below 40 until transformed into a white non-transbegins to fall gentle heat is applied, and

the mixture should'be kept at 5055 (3.,

until theliqui-d becomes nearly transparent.

When it becomes soluble in alcohol-free chloroform and insoluble in acetone, (as

shown by treating vsmall test portions) it is partially hydrated. For this purpose, a mixture of 5.0 to 65 litres of Water and 60 litres of glacial acetic acid is slowly added, with constant stirring. The mixture is then kept at 40750 (1., for 12 to 16 hours until in chloroform and soluble in acetone The acetylated cellulose is then precipi-' tated by slowly pouring into a large volume of cold'water, it is then washed until neutral and ilried at a temperature of 3550 C;

This product is then dissolved in any of i the known solvents such as acetone, glacial acetic acid, lactic acid, pyridine, nitro-benzene, epichlorhydrin, formic acid, acetylene tetrachloride, tetrachlorethane, ethyl acetate or chloroform and alcohol.

This solution may then be poured on plates, or forced through spinarets, slitsor Solidification may be accomplished by evaporation, 'or precipitation may be aided by the use of any of the known precipitants, such as water, ben zol, alcohol, ca-rbon' tetrachlorideor' toluene.

Cellulose formates may be produced from any of the previously mentioned cellulosev products of mature driedcorn-cobs by the action of strong fOI'mIQ aCid, upon them,

using as a catalyzer or'condensing medium,

sulphuric acid or any other chemical or substance which may be found suitable.=

Eammple 3.-F0rmati0n of cellulose I 1 formate.

l-.;l8 grams ofldriedcorn-cob cellulose, preparedas' previously described from mature 'dned. corn-cobs, preferably bleached, are

treated'with' 100-gms. of formic acid of sp.

gr. 1.20 or 1.22, and lQ'gms. of concentrated 'methods may be used.

sulphuric acid, for 16 hours at 30-35 C. After thinning with more formic acid the heavy Viscous mass is separated from unacted uponcellulose, (e. g. by filtration) precipitated in a large bulk of water, washed to neutrality and dried at a low temperature.

This product is then dissolved in one of the usual solvents, such as formic acid, lactic acid, zinc chloride or a solution of chromates or bichromates.

This solution may then be poured on plates, or forced through spinarets, slits or into moulds. Solidification may be accomplished by evaporation, or precipitation may be aided by the use of solutions of methyl,

ethyl or amyl alcohol, acetone, chloroform, carbon tetrachloride, acetylene" tetrachloride, ethyl acetate, amyl acetate, nitrobenzene, aniline or dilute acetic, sulfuric or hydrochloric acid. (Other cellulose forinate solvents which may be used are-' alkali iodides and bromides, calcium chloride ammonium nitrate, alkaline earth and other metallic nitrates, cupric chloride, cupric acetate, cuprous chloride, alkali xanthates, aniline salts and alkaline salts of aromatic monoand poly-sulfuric acids).

f In the formation of cellulose plastic s, cellulose esters prepared from mature. dry corn-cobs by any of the previously mentioned g (or other known or possible) These products may be converted into the acetate or formate according to the methods abovegiven. .In addition any of the following chemicals or substances may be added acetylene tetrachloride,. carbon -tetrachlo rlde, glycerol, phenol, casein, albumen,

formalin, cresols, amyl lactate, amyl acetate,

in the or employed in the process :--camphor,

taining organic ac-id. esters of cellulose I which comprises reacting uponmature corn cob material with an organic acidesterify- 1 ing agent. 2. A process of making a product containing fatty acid esters of cellulose which comprises reacting upon mature corn cob material with a fatty acid esterifying agentr 3. A 'processwhich comprises subjecting mature 'corn cob material to the. action of acetylating reagents.

4. A process which'compr-ises' comminut ing mature dried corn cobs, bleaching the same, ,drying andsubjecting the dried mate. rial to acetylation reactions.

5. A cellulose acetate product containing in addition to cellulose acetate,- the reaction weenie Q corn oobs with a fatty acfl, such reaction products being soluble in cellulose ester solvents. no

In testimony whereof 1 hereto aflix my signature.

N ORMAN E. DITMAN. 

